Use handle lists in Map::FindTransitionedMap.

src/hydrogen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4077 matching lines @@
   SmallMapList* maps = prop->GetReceiverTypes();
   bool todo_external_array = false;
 
   static const int kNumElementTypes = kElementsKindCount;
   bool type_todo[kNumElementTypes];
   for (int i = 0; i < kNumElementTypes; ++i) {
     type_todo[i] = false;
   }
 
   // Elements_kind transition support.
-  MapList transition_target(maps->length());
+  MapHandleList transition_target(maps->length());
   // Collect possible transition targets.
-  MapList possible_transitioned_maps(maps->length());
+  MapHandleList possible_transitioned_maps(maps->length());
   for (int i = 0; i < maps->length(); ++i) {
     Handle<Map> map = maps->at(i);
     ElementsKind elements_kind = map->elements_kind();
     if (elements_kind == FAST_DOUBLE_ELEMENTS ||
         elements_kind == FAST_ELEMENTS) {
-      possible_transitioned_maps.Add(*map);
+      possible_transitioned_maps.Add(map);
     }
   }
   // Get transition target for each map (NULL == no transition).
   for (int i = 0; i < maps->length(); ++i) {
     Handle<Map> map = maps->at(i);
-    Map* transitioned_map =
+    Handle<Map> transitioned_map =
         map->FindTransitionedMap(&possible_transitioned_maps);
     transition_target.Add(transitioned_map);
   }
 
   int num_untransitionable_maps = 0;
   Handle<Map> untransitionable_map;
   for (int i = 0; i < maps->length(); ++i) {
     Handle<Map> map = maps->at(i);
     ASSERT(map->IsMap());
-    if (transition_target.at(i) != NULL) {
+    if (!transition_target.at(i).is_null()) {
       object = AddInstruction(new(zone()) HTransitionElementsKind(
-          object, map, Handle<Map>(transition_target.at(i))));
+          object, map, transition_target.at(i)));
     } else {
       type_todo[map->elements_kind()] = true;
       if (map->elements_kind() >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND) {
         todo_external_array = true;
       }
       num_untransitionable_maps++;
       untransitionable_map = map;
     }
   }
 
@@ skipping 2878 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal